Bestinvest vs AJ Bell: The Fee Breakdown That Shows Which ISA Platform Is Actually Cheaper

AJ Bell charges a flat 0.25% annual platform fee on funds held in an ISA, SIPP, or dealing account. The fee drops to 0.10% on amounts between £250,000 and £500,000, and disappears entirely above £500,000. AJ Bell is authorised by the FCA (FRN 209812) and has over 673,000 customers.

Bestinvest charges 0.40% on third-party funds, dropping to 0.20% between £250,001 and £500,000, then 0.10% up to £1 million. Above £1 million, there's no platform fee at all. Bestinvest is part of the Evelyn Partners group (formerly Tilney Smith & Williamson) and is also FCA-authorised.

On shares, ETFs, and investment trusts, AJ Bell caps the platform charge at just £3.50 per month (£42 per year) — regardless of portfolio size. Bestinvest charges the same percentage tiers as funds on these holdings, but caps the total annual service fee at £2,000 per year.

For a £50,000 fund-only ISA, the annual platform cost comparison is stark:

• AJ Bell: £125 per year
• Bestinvest: £200 per year

That's a £75 gap. But platform fees tell only half the story.

Fund dealing is free at Bestinvest. Every buy, every sell, every switch — £0. AJ Bell charges £1.50 per fund trade, or £1.50 through regular investing.

Share dealing costs £4.95 per trade at Bestinvest and £5.00 at AJ Bell (dropping to £3.50 if you traded 10+ times the previous month). For regular share investments via direct debit, AJ Bell charges just £1.50 — one of the cheapest regular investing rates in the UK.

The dealing cost difference compounds over a year. An active ISA investor making two fund trades per month pays £36 annually at AJ Bell — nothing at Bestinvest. At four trades per month, the AJ Bell dealing bill hits £72. At six trades per month, it's £108 — now eating into more than half of the platform fee saving on a £50,000 portfolio.

Add those dealing charges to the platform fee for a £50,000 ISA with two monthly fund trades:

• AJ Bell: £125 + £36 = £161 per year
• Bestinvest: £200 + £0 = £200 per year

Still AJ Bell ahead, but by £39 rather than £75. The more you trade, the smaller the gap. At roughly seven fund trades per month on a £50,000 ISA, the total costs equalise. Beyond that threshold, Bestinvest is cheaper.

For buy-and-hold investors who rebalance once or twice a year, AJ Bell's dealing charges are negligible. For active fund switchers — those chasing performance, rebalancing quarterly, or moving between sectors — Bestinvest's free dealing is a material advantage.

Both platforms offer managed portfolio options for investors who prefer a hands-off approach. The fee difference here reverses the headline comparison entirely.

Bestinvest's ready-made portfolios carry a 0.20% platform fee — below AJ Bell's 0.25%. On a £50,000 portfolio, that's £100 versus £125 per year. Over a decade with 5% annual growth, the compound saving from that 0.05% difference amounts to several hundred pounds.

AJ Bell's Ready-Made Portfolios layer their own ongoing charge on top of the platform fee. Bestinvest's portfolios include the management fee within the 0.20% platform charge, though the underlying fund charges (OCF) still apply on both platforms — typically 0.10% to 0.30% depending on the fund mix.

For ISA investors who want a single managed portfolio and rarely trade, Bestinvest is genuinely cheaper. The 0.20% rate applies to the first £250,000 — covering the vast majority of ISA investors. Compare this to our analysis of AJ Bell's fee structure, where the 0.25% rate applies universally up to £250,000.

Both platforms charge a foreign exchange fee when you buy or sell non-GBP investments. AJ Bell charges 0.75%, capped at a maximum per-transaction charge. Bestinvest charges 0.95% with no stated cap — a meaningful difference for investors regularly buying US-listed ETFs or international stocks.

For an investor buying £500 of a Vanguard S&P 500 ETF listed in USD, the FX cost is £3.75 at AJ Bell versus £4.75 at Bestinvest. Over a year of monthly US purchases, the difference adds up to £12. On larger monthly investments of £2,000, the annual FX gap widens to £48.

Neither platform matches the FX rates offered by newer entrants. Trading 212 offers commission-free trading with competitive FX rates, and Freetrade's Plus plan brings FX fees down to 0. See <a href="/platforms/freetrade">Freetrade's commission-free model</a> for more details.39%. If international investing is a core part of your strategy, both Bestinvest and AJ Bell sit in the middle of the pack — cheaper than Hargreaves Lansdown's higher overall costs, but pricier than the app-based challengers.

Bestinvest offers a flexible ISA. Withdraw £5,000 in June, replace it by the following April, and you haven't used any additional allowance. AJ Bell's ISA is not flexible — once you withdraw, that portion of your £20,000 annual allowance is gone.

For most long-term ISA investors building a retirement pot, flexibility is irrelevant. You're not touching the money for decades. But for anyone using their ISA as a medium-term savings vehicle — bridging a house purchase, covering a career break, managing lumpy freelance income — Bestinvest's flexible ISA is a genuine differentiator that no fee comparison captures.

Under current HMRC ISA rules, flexible ISAs let you withdraw and replace money within the same tax year without it counting against your annual allowance. Only some providers offer this — it's a feature of the provider, not the ISA type.

AJ Bell does offer a Lifetime ISA with the 25% government bonus for under-40s saving for a first home or retirement. Bestinvest doesn't offer a LISA. If you're eligible and haven't yet used your Lifetime ISA allowance, that's a point in AJ Bell's favour that outweighs any platform fee discussion — the 25% bonus is worth up to £1,000 per year on the maximum £4,000 annual contribution.

For a full comparison of ISA types and providers, see our ISA hub which covers the full range of tax-free savings options. See our analysis on AJ Bell SIPP drawdown costs in 2026.

The answer depends on three variables: what you hold, how often you trade, and how much you invest.

Under £30,000 in funds, rarely trading: AJ Bell wins. The 0.15% platform fee saving compounds to more than you'll ever pay in dealing charges. Total annual cost on £25,000: AJ Bell £62.50, Bestinvest £100.

£30,000–£100,000 in funds, trading monthly: Close call. AJ Bell's lower platform fee is partially offset by dealing charges. On a £75,000 ISA with two monthly trades: AJ Bell £223.50 versus Bestinvest £300. AJ Bell still ahead, but the gap is narrower as a percentage — and the difference matters less as portfolio returns dwarf fee savings.

Ready-made portfolios at any size: Bestinvest wins. The 0.20% vs 0.25% difference grows with portfolio size. On £100,000: Bestinvest £200, AJ Bell £250. Over 10 years with growth, Bestinvest saves you over £800.

Large share/ETF portfolios over £50,000: AJ Bell wins decisively. The £3.50/month cap means you pay just £42 per year regardless of whether you hold £50,000 or £500,000 in shares. Bestinvest's percentage-based charging on shares means costs scale linearly — on a £200,000 ETF portfolio, that's £800 per year versus AJ Bell's £42.

Mixed portfolios with international exposure: Consider the total cost including FX. AJ Bell's 0.75% FX fee versus Bestinvest's 0.95% tilts the balance further toward AJ Bell for globally diversified investors.

Neither platform is universally cheaper. The best choice depends on your specific investing behaviour — not the headline rate. For additional platform comparisons, see our investing hub.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions.